As war planes from Israel continue to pound Gaza — and with a massive ground offensive of Israeli troops expected any day — the rationale behind the massacre unleashed by Hamas on the weekend that prompted Israel's severe retaliation may certainly seem unclear. Hamas's attacks, which have killed more than 1,200 Israelis, prompted Israeli Prime Minister Benjamin Netanyahu to issue an official declaration of war that has resulted in the deaths of at least 1,100 people in Gaza and an estimated 250,000 people left homeless. The militant group's ultimate goal is the destruction of Israel and to establish an Islamist...